Buggy code:
float areaHeight ; private boolean fadeScrollBars = true ; private boolean smoothScrolling = true ; float fadeAlpha ; float fadeAlphaSeconds = 1 ; float fadeDelay ; float fadeDelaySeconds = 1 ; boolean cancelTouchFocus = true ; boolean flickScroll = true ; float velocityX ; float velocityY ; float flingTimer ; private boolean overscrollX = true ; private boolean overscrollY = true ; float flingTime = 1.0F ; private float overscrollDistance = 50 ; private float overscrollSpeedMin = 30 ; private float overscrollSpeedMax = 200 ; private boolean forceScrollX ; private boolean forceScrollY ; private boolean disableX ; private boolean disableY ; private boolean clamp = true ; private boolean scrollbarsOnTop ; private boolean variableSizeKnobs = true ; int draggingPointer = - 1 ; public ScrollPane ( Actor widget ) { } public ScrollPane ( Actor widget , Skin skin ) { } public ScrollPane ( Actor widget , Skin skin , String styleName ) { } public ScrollPane ( Actor widget , ScrollPane . ScrollPaneStyle style ) { } void resetFade ( ) { } void cancelTouchFocusedChild ( InputEvent event ) { } public void cancel ( ) { } void clamp ( ) { } public void setStyle ( ScrollPane . ScrollPaneStyle style ) { } public ScrollPane . ScrollPaneStyle getStyle ( ) { } public void act ( float delta ) { } public void layout ( ) { } @ Override public void draw ( Batch batch , float parentAlpha ) { } public void fling ( float flingTime , float velocityX , float velocityY ) { } public float getPrefWidth ( ) { } public float getPrefHeight ( ) { } public float getMinWidth ( ) { } public float getMinHeight ( ) { } public void setWidget ( Actor widget ) { } public Actor getWidget ( ) { } public void addActor ( Actor actor ) { } public void addActorAt ( int index , Actor actor ) { } public void addActorBefore ( Actor actorBefore , Actor actor ) { } public void addActorAfter ( Actor actorAfter , Actor actor ) { } public boolean removeActor ( Actor actor ) { } public Actor hit ( float x , float y , boolean touchable ) { } protected void scrollX ( float pixelsX ) { } protected void scrollY ( float pixelsY ) { } protected void visualScrollX ( float pixelsX ) { } protected void visualScrollY ( float pixelsY ) { } protected float getMouseWheelX ( ) { } protected float getMouseWheelY ( ) { } public void setScrollX ( float pixels ) { } public float getScrollX ( ) { } public void setScrollY ( float pixels ) { } public float getScrollY ( ) { } public void updateVisualScroll ( ) { } public float getVisualScrollX ( ) { } public float getVisualScrollY ( ) { } public float getVisualScrollPercentX ( ) { } public float getVisualScrollPercentY ( ) { } public float getScrollPercentX ( ) { } public void setScrollPercentX ( float percentX ) { } public float getScrollPercentY ( ) { } public void setScrollPercentY ( float percentY ) { } public void setFlickScroll ( boolean flickScroll ) { } public void setFlickScrollTapSquareSize ( float halfTapSquareSize ) { } public void scrollTo ( float x , float y , float width , float height ) { } public void scrollTo ( float x , float y , float width , float height , boolean centerHorizontal , boolean centerVertical ) { } public float getMaxX ( ) { } public float getMaxY ( ) { } public float getScrollBarHeight ( ) { } public float getScrollBarWidth ( ) { } public float getScrollWidth ( ) { } public float getScrollHeight ( ) { } public boolean isScrollX ( ) { } public boolean isScrollY ( ) { } public void setScrollingDisabled ( boolean x , boolean y ) { } public boolean isLeftEdge ( ) { } public boolean isRightEdge ( ) { } public boolean isTopEdge ( ) { } public boolean isBottomEdge ( ) { } public boolean isDragging ( ) { } public boolean isPanning ( ) { } public boolean isFlinging ( ) { } public void setVelocityX ( float velocityX ) { } public float getVelocityX ( ) { } public void setVelocityY ( float velocityY ) { } public float getVelocityY ( ) { } public void setOverscroll ( boolean overscrollX , boolean overscrollY ) { } public void setupOverscroll ( float distance , float speedMin , float speedMax ) { } public void setForceScroll ( boolean x , boolean y ) { } public boolean isForceScrollX ( ) { } public boolean isForceScrollY ( ) { } public void setFlingTime ( float flingTime ) { } public void setClamp ( boolean clamp ) { } public void setScrollBarPositions ( boolean bottom , boolean right ) { } public void setFadeScrollBars ( boolean fadeScrollBars ) { } public void setupFadeScrollBars ( float fadeAlphaSeconds , float fadeDelaySeconds ) { } public void setSmoothScrolling ( boolean smoothScrolling ) { } public void setScrollbarsOnTop ( boolean scrollbarsOnTop ) { } public boolean getVariableSizeKnobs ( ) { } public void setVariableSizeKnobs ( boolean variableSizeKnobs ) { } public void setCancelTouchFocus ( boolean cancelTouchFocus ) { } public void drawDebug ( ShapeRenderer shapes ) { <START_BUG> drawDebugBounds ( shapes ) ; <END_BUG> applyTransform ( shapes , computeTransform ( ) ) ; if ( ScissorStack . pushScissors ( scissorBounds ) ) { drawDebugChildren ( shapes ) ; ScissorStack . popScissors ( ) ; } resetTransform ( shapes ) ; } public static class ScrollPaneStyle { public Drawable background ; public Drawable corner ; public Drawable hScroll ; public Drawable hScrollKnob ; public Drawable vScroll ; public Drawable vScrollKnob ; public ScrollPaneStyle ( ) { } public ScrollPaneStyle ( Drawable background , Drawable hScroll , Drawable hScrollKnob , Drawable vScroll , Drawable vScrollKnob ) { } public ScrollPaneStyle ( ScrollPane . ScrollPaneStyle style ) { } } }

Fix:
shapes . flush ( ) ;